there is SHOULDER SPRING BAR , look at bottom side of your watch , there is shoulder spring bar just as normal watch. you need to squeeze to take off watch band.hard to get strap for this watch, its is Discontinued.
this is a chronograph I think and what you are referring to as the long second hand is actually the chrono hand the seconds hand is at 9 oclock on this model and the smaller hand that is moving simultanusly is actually the chrono revolution counter